The objective of this study is to investigate how a protein acquires its unique native conformation by equilibrium denaturation studies and by analyzing the kinetics of unfolding and refolding of carbonic anhydrase and its polypeptide fragments. Specifically, we plan to study: (1) Functional and conformational aspects of purified polypeptide fragments and their comparison with the conformation of the corresponding polypeptide segment in the intact protein. (2) Detailed kinetic analysis of the unfolding and refolding processes of the protein and its fragments. (3) Effect of Zn(II) on the thermodynamics and kinetics of unfolding and refolding of the protein and selected polypeptide fragments. The results of these studies will also contribute to our understanding of the equilibrium and kinetic aspects of conformational changes of proteins in general and carbonic anhydrase in particular. They will provide fundamental knowledge on the causes of abnormalities in cellular structural organization to clinical and medical researchers, particularly those in the field of respiratory diseases, since carbonic anhydrase is one of the essential enzymes involved in this important physiological function.